Various different clothing items, such as pants, shirts, coats, hats, and the like are printed with camouflage patterns. The camouflage patterns are designed so that the wearer of the clothing article remains hard to detect visually in a particular environment. Camouflaged clothing articles are used regularly by hunters, outdoorsmen, and the military.
Military personnel, for instance, are typically issued camouflaged pattered garments known at battle dress uniforms. The camouflage pattern appearing on the garments typically consists of 3 to 8 colors chosen specifically to blend into a particular environment. For instance, camouflage patterns have been designed for desert, woodland and jungle environments as well as urban environments, and the like. Camouflage patterns have become more and more sophisticated in the recent past. For instance, U.S. Pat. No. 6,805,957, which is incorporated herein by reference, discloses a camouflage pattern system that is intended to provide concealment properties in both the human visible light range and the near infrared range. The camouflage pattern, for instance, may include at least 4 colorings using dyes that in combination produce a range of reflectance values similar to that of the background environment that the individual person will be wearing the garment in. The camouflage pattern system disclosed in the '957 patent includes a macro pattern that is disruptive of the wearer's shape and a micro pattern having sharp edge units of a size capable of blending the wearer into its background.
Although many camouflaged garments are well suited to providing camouflaged properties to the wearer in the visible region of light and to some extent in the near infrared region, many camouflage patterns lose their effectiveness at longer wavelengths of light. For example, night vision goggles detect reflectances in the infrared wavelength range and produce an image that can be visibly seen by the user. More specifically, night vision goggles sense and amplify reflective visible starlight, or other ambient light, in image intensification tubes. In the past, most night vision goggles operated in the near infrared wavelength range of less than 900 nm.
Recently, however, various improvements have been made in night vision detection equipment allowing the goggles to operate at longer wavelengths. At longer wavelengths, such as wavelengths greater than 900 nm, many camouflage garments begin to lose their camouflage properties. In particular, at longer wavelengths, the colors contained in the camouflage patter exhibit the same reflectance characteristics. Thus, when a camouflaged garment is viewed through night vision goggles that operate at longer wavelengths, the colors of the camouflage pattern begin to reflect ambient light back at similar intensities thereby presenting an object as a single intensity silhouette and making the garment wearer easily detectable.
In view of the above, a need currently exists for a fabric and garment containing a camouflage pattern that retains its camouflage light reflectance characteristics even when viewed at wavelengths greater than 900 nm. In particular, a need exists for a method and system of maintaining color or reflectance separation in a camouflage pattern at relatively long wavelengths in the infrared range.